The depressor septi nasi is a facial muscle of expression that assists the alar part of the nasalis muscle in widening the nasal opening. It is attached to both the maxilla, above the medial incisor tooth, and the nasal septum, and its actions consist of pulling the nasal septum inferiorly in order to widen the nasal opening.
The depressor septi nasi is innervated by the buccal branches of the facial nerve, and its blood supply comes from the facial artery.
The depressor septi nasi is classified as a mixed muscle, meaning that it contains both skeletal and smooth muscle fibers. As such, it is also a striated muscle that is primarily responsible for facial expression, specifically for widening the nostrils.
The depressor septi nasi is the only muscle of facial expression that is present in the nose. It is the main muscle responsible for the widening of the nasal opening, and therefore plays an important role in nasal airflow.
When the depressor septi nasi contracts, it compresses the alar part of the nasalis muscle, which in turn pulls the nasal septum inferiorly. This action of the depressor septi nasi enables it to widen the nasal opening and facilitate nasal airflow.
The depressor septi nasi is innervated by the buccal branches of the facial nerve. Its contraction is stimulated by nerve impulses that originate in the facial nerve, and they are transmitted from the buccal branches of the facial nerve to the depressor septi nasi muscles. The facial nerve also carries the motor signals that allow for facial expressions, and the depressor septi nasi is one of the muscles that receive those signals.
The depressor septi nasi also receives its blood supply from the facial artery. The facial artery is a branch of the external carotid artery, and it supplies the face, neck, and scalp with oxygenated blood. The artery branches into the buccal branches of the facial nerve, which in turn supplies blood to the depressor septi nasi.
The depressor septi nasi is therefore an important muscle of facial expression that assists the alar part of the nasalis muscle in widening the nasal opening. It is innervated by the buccal branches of the facial nerve, and receives its blood supply from the facial artery.
The depressor septi nasi is an important muscle of facial expression that helps to maintain the nasal cavity's normal functions. Its contraction enables it to widen the nasal opening and facilitate nasal airflow, and it is the only muscle of facial expression that is present in the nose.
In addition, the depressor septi nasi receives its nerve supply from the buccal branches of the facial nerve, and its blood supply from the facial artery. Therefore, its proper functioning is essential for normal nasal cavity functions, and it should be kept healthy in order for the nose to maintain its normal functions.
